Speaker Device For Mobile Terminal

ABSTRACT

A speaker device for use in a mobile terminal includes a speaker frame with a speaker unit mounted therein, and a frame cover provided at the rear side of the speaker frame to form a resonance space between the speaker frame and the frame cover. Sound that is output in a forward direction of the speaker unit is emitted to a front space of the speaker frame, and sound that is output to the rear of the speaker unit is emitted through the resonance space. The speaker device provides the resonance space at the rear side of the speaker frame to reinforce the output of midrange and bass tones, thereby reproducing the original sound as accurately as possible. The speaker device enables a user to enjoy vivid sound when reproducing a multimedia file or viewing a digital multimedia broadcast (DMB) program on a small-sized device, such as a mobile terminal.

CROSS-REFERENCE TO RELATED APPLICATION

This is a continuation application of U.S. patent application Ser. No.11/603,192, filed Nov. 22, 2006, now U.S. Pat. No. 8,331,599, entitled“Speaker Device for Mobile Terminal,” which claims the benefit under 35U.S.C. §119(a) of an application entitled “Speaker Device for MobileTerminal” filed at the Korean Intellectual Property Office on Jul. 28,2006 and assigned Application No. 2006-71447, the entire disclosures ofboth of said prior applications being hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a mobile terminal. More particularly,the present invention relates to a speaker device for a mobile terminalthat improves the sound pressure level, articulation and acousticdistortion rate of output sound, and reinforces output of midrange andbass tones to reproduce the original sound as accurately as possible.

2. Description of the Related Art

Generally, mobile terminals refer to handheld devices used for wirelesscommunications between users or between a user and a service providerthrough a base station. Mobile terminals can offer various functions orservices, including voice communication, short message service, mobilebanking, TV broadcasts, online games, video-on-demand and variouscontent transmissions.

Mobile terminals can be classified into a bar type, a flip type and afolder type according to their shapes. A bar-type mobile terminal has asingle housing provided with data input/output means such as acommunication circuit, a microphone and an earpiece. A flip-type mobileterminal has a bar-shaped housing and a flip cover rotatably connectedto the housing. A folder-type mobile terminal has a pair of housingsrotatable about each other and having input/output means properlydistributed thereon. Recently, new designs with improved portability andconvenience, such as a slide type, have been launched to meet thediverse needs and tastes of users.

Mobile terminals have gone beyond merely being telephones or shortmessage devices, and now integrate additional functions, such as games,music, motion picture file transmission, multimedia services and digitalmultimedia broadcasting (“DMB”) services.

Even before the commercialization of multimedia and DMB services, a thinfilm transistor (“TFT”), instead of a monochromatic liquid crystaldisplay device, was used for a display unit of a mobile terminal toproduce high-quality color pictures. The TFT display unit has a highcapacity sufficient to offer multimedia and DMB services to the mobileusers.

To provide a speaker device suitable for the multimedia and DMBservices, a conventional mobile terminal includes additional speakerunits for outputting stereo sound, as well as a speaker unit foroutputting a received voice or a bell sound.

However, such additional speaker units cannot fully exert their capacitydue to the limited space within a mobile terminal. The limited spacereduces the sound pressure output and articulation level, and increasesthe acoustic distortion rate. Because the speaker units are mounted inthe limited space of the mobile terminal, the sound output from thespeaker units cannot be accurately reproduced in the low bass range,which does not meet the users' need to enjoy the original soundreproduced as accurately as possible when using multimedia services orviewing DMB programs.

Accordingly, a need exists for an improved speaker device thataccurately reproduces sound in a compact mobile terminal

SUMMARY OF THE INVENTION

An object of exemplary embodiments of the present invention is toprovide a speaker device mounted within a mobile terminal capable ofaccurately reproducing bass tones.

Another object of the present invention is to provide a speaker devicefor a mobile terminal that enhances bass tones to reproduce the originalsound as accurately as possible during multimedia or DMB services.

A speaker device for use in a mobile terminal includes a speaker framewith a speaker unit mounted therein, and a frame cover provided at therear side of the speaker frame to form a resonance space between thespeaker frame and the frame cover. Sound that is output in a forwarddirection of the speaker unit is emitted to a front space of the speakerframe, and sound that is output to the rear of the speaker unit isemitted through the resonance space.

Other objects, advantages and salient features of the invention willbecome apparent from the following detailed description, which, taken inconjunction with the annexed drawings, discloses exemplary embodimentsof the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the presentinvention will be more apparent from the following detailed descriptiontaken in conjunction with the accompanying drawings, in which:

FIG. 1 is an elevational view in partial cross section of a speakerdevice for a mobile terminal according to an exemplary embodiment of thepresent invention;

FIG. 2 is an exploded perspective view of a speaker device with theresonance structure illustrated in FIG. 1; and

FIG. 3 is an assembled perspective view of the speaker device of FIG. 2.

Throughout the drawings, the same drawing reference numerals will beunderstood to refer to the same elements, features, and structures.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Hereinafter, exemplary embodiments of the present invention aredescribed with reference to the accompanying drawings. Descriptions ofwell-known functions and constructions thereof are omitted for clarityand conciseness.

FIG. 1 is an elevational view in partial cross section of a speakerdevice 100 for a mobile terminal according to an exemplary embodiment ofthe present invention. As illustrated in FIG. 1, the speaker device 100includes a speaker unit 103 within a speaker frame 101 and a frame cover102 provided at the rear side of the speaker frame 101 to form aresonance space 113 between the rear surface of the speaker frame 101and the frame cover 102.

More specifically, the speaker unit 103 is mounted at the center part ofthe speaker frame 101. The speaker frame 101 has a front space 111protected by a protector 104. The frame cover 102 is provided at therear side of the speaker frame 101. The front space 111 of the speakerframe 101 and the resonance space 113 are separated by a yoke 131 of thespeaker unit 103. The front space 111 and the resonance space 113 areconnected through at least one vent hole 115.

The speaker frame 101 is preferably injection molded. The resonancespace 113 having one side opened is formed when the frame cover 102 iscoupled to the rear side of the speaker frame 101. Preferably, the framecover 102 has a substantially flat-plate shape.

The speaker unit 103 includes a yoke 131, a magnetic member 133, a voicecoil 137 and a vibration plate 139. The yoke 131 is placed atapproximately the center of the speaker frame 101 to separate the frontspace 111 of the speaker frame 101 from the resonance space 113 formedat the rear side of the speaker frame 101. The magnetic member 133 isattached to the front surface of the yoke 131 and is surrounded by thevoice coil 137. The vibration plate 139 is provided on the front surfaceof the voice coil 137 so that the vibration plate faces the magneticmember 133 and the voice coil 137.

When an electric signal, such as an audio signal, is applied to thespeaker unit 103, an electric field generated from the voice coil 137and a magnetic field of the magnetic member 133 interact to vibrate thevibration plate 139, thereby generating sound corresponding to theapplied signal. A metallic plate 135 provided on the front surface ofthe magnetic member 133 induces the magnetic field to be distributedtoward the voice coil 137, which facilitates vibration of the vibrationplate 139 by the applied signal.

The protector 104 is mounted at the front side of the speaker frame 101to protect the speaker unit 103. The protector 104 also allows soundgenerated from the speaker unit 103 to be emitted outwardly. Soundgenerated from the speaker unit 103 is emitted through the protector 104in a forward direction of the speaker device 100. However, sound outputto the rear of the speaker unit is emitted in a backward direction, thatis, through the resonance space 113.

In a conventional speaker device having no resonance space 113, soundemitted to the rear of a speaker unit leaks outside a mobile terminal,without being transferred to the user. To the contrary, in the speakerdevice 100 according to an exemplary embodiment of the presentinvention, sound traveling to the rear of the speaker unit 103 causesresonance within the resonance space 113, thereby reinforcing productionof midrange and bass tones and reproducing the original sound asaccurately as possible.

The speaker device 100 may additionally include a duct hole 121 forconnecting the resonance space 113 to the outside of the speaker frame101. The duct hole 121 is preferably formed between the resonance space113 and an outer surface of the speaker device 100, as shown in FIG. 1.The duct hole 121 allows the sound output to the rear of the speakerunit 103 to be emitted outside after causing resonance within theresonance space 113. The duct hole 121 substantially prevents theconsecutively output waves of sound from interfering each another. Whenthe resonance space 113 is formed large enough to prevent a sound waveoutput to the rear of the speaker unit 103 from interference from asubsequent sound wave after causing resonance, the duct hole 121 may beomitted. Preferably, the duct hole 121 is formed at a portion extendingrearwardly from the speaker frame 101.

The speaker device according to exemplary embodiments of the presentinvention is applicable to a slim and small-sized mobile terminal.Because the speaker device has a limitation in providing a resonancespace large enough to substantially prevent interference between soundwaves, the speaker device preferably includes the duct hole 121.

FIG. 2 is an exploded perspective view of a speaker device 200 havingthe resonance structure illustrated in FIG. 1. FIG. 3 is an assembledperspective view of the speaker device 200 of FIG. 2. As illustrated inFIGS. 2 and 3, the speaker device 200 having the resonance structureaccording to exemplary embodiments of the present invention includes aspeaker frame 201 with a speaker unit (not shown) mounted therein and aframe cover 202 provided at the rear side of the speaker frame 201.Drawing reference numerals or detailed explanations of the elements thatare easily understandable in view of the speaker device of FIG. 1 areomitted in the following description.

The speaker frame 201 has a protruded portion 211 at the front surfacethereof. A protector 204 is provided inside the protruded portion 211.The speaker unit 200 is mounted within a space formed by the protrudedportion 211 and the protector 204.

The frame cover 204 is provided at the rear side of the speaker frame201 to form a resonance space. The speaker frame 201 and the frame cover202 have grooves 221 a and 221 b for forming a duct hole. When the framecover 202 is coupled to the speaker frame 201, the grooves 221 a and 221b face each other and form a duct hole.

While the duct hole illustrated in FIG. 1 extends from the resonancespace 113 and backwardly outward from the speaker frame 101, the ducthole actually applied to a product as illustrated in FIGS. 2 and 3 maybe formed in a portion extending in a horizontal direction of thespeaker frame 201. The duct hole opens toward an axis through a centerof the speaker device 200, as shown in FIGS. 2 and 3. The duct hole thatconnects the resonance space to the outside of the speaker frame 201 isformed in a portion extending horizontally from the speaker frame 201 sothat the sound causing resonance within the resonance space may beemitted laterally from the speaker frame 201.

A signal cable 138 extending from the speaker unit applies an audiosignal to the speaker unit. The signal cable 138 reaches outside thespeaker frame through the duct hole.

In the speaker device 200 having the above structure, sound emitted tothe rear of the speaker unit causes resonance within the resonancespace, thereby reinforcing production midrange and bass tones andreproducing the original sound as accurately as possible.

As explained above, the speaker device according to exemplaryembodiments of the present invention provides the resonance space at therear side of the speaker frame to reinforce the output of midrange andbass tones, thereby reproducing the original sound as accurately aspossible. The speaker device enables a user to enjoy vivid sound whenreproducing a multimedia file or viewing a DMB program on a small-sizeddevice, such as a mobile terminal.

Although exemplary embodiments of the present invention have beendescribed for illustrative purposes, those skilled in the art willappreciate that various modifications, additions and substitutions arepossible, without departing from the scope and spirit of the inventionas disclosed in the accompanying claims, including the full scope ofequivalents thereof.

What is claimed is:
 1. A speaker device for use in a mobile terminal,comprising: a speaker frame with a speaker unit mounted therein; and aframe cover provided at the rear side of the speaker frame to form aresonance space between the speaker frame and the frame cover, whereinsound output in a forward direction of the speaker unit is emitted to afront space of the speaker frame, and sound output to the rear of thespeaker unit is emitted through the resonance space.
 2. The speakerdevice according to claim 1, further comprising at least one vent holeconnecting the front space of the speaker frame and the resonance space.3. The speaker device according to claim 1, further comprising a ducthole formed at an edge portion of the speaker frame to connect theresonance space to the outside of the speaker frame.
 4. The speakerdevice according to claim 3, further comprising at least one signalcable extending from the speaker unit and passing through the duct hole.5. The speaker device according to claim 1, wherein the speaker unitcomprises a yoke disposed approximately at the center of the speakerframe; a magnetic member attached to the front surface of the yoke andplaced in the front space of the speaker frame; a voice coil disposedaround the magnetic member; and a vibration plate disposed in the frontspace of the speaker frame such that the vibration plate faces themagnetic member and the voice coil.
 6. The speaker device according toclaim 5, further comprising a protector mounted at the front side of thespeaker frame to protect the speaker unit.
 7. The speaker deviceaccording to claim 5, wherein the speaker unit further comprises ametallic plate disposed on the front surface of the magnetic member toinduce a magnetic field to be distributed toward the voice coil.
 8. Thespeaker device according to claim 1, wherein the frame cover has asubstantially flat-plate shape.
 9. The speaker device according to claim1, wherein the speaker frame is injection molded and the resonance spacehas one open side formed by coupling the frame cover to the rear side ofthe speaker frame.
 10. The speaker device according to claim 3, whereinthe speaker frame and the frame cover have grooves that face each otherand form the duct hole when the frame cover is coupled to the speakerframe.
 11. The speaker device according to claim 3, wherein the ducthole is formed at a portion extending in a horizontal direction of thespeaker frame.
 12. A speaker device for use in a mobile terminal,comprising: a speaker frame with a speaker unit mounted therein, and afront space being formed in the speaker frame; a frame cover connectedto the speaker frame to form a resonance space between the speaker frameand the frame cover; a vent hole in the speaker frame to connect thefront space to the resonance space; and a duct hole formed between theresonance space and an outer surface of the speaker device; whereinsound output in a first direction is emitted to the front space of thespeaker frame, and sound output in a second and substantially oppositedirection is emitted through the resonance space.
 13. The speaker deviceaccording to claim 12, wherein a signal cable extends from the speakerunit and passes through the duct hole.
 14. The speaker device accordingto claim 12, wherein the speaker unit includes a yoke disposedapproximately at the center of the speaker frame; a magnetic memberattached to the front surface of the yoke and disposed in the frontspace of the speaker frame; a voice coil disposed around the magneticmember; and a vibration plate disposed in the front space of the speakerframe such that the vibration plate faces the magnetic member and thevoice coil.
 15. The speaker device according to claim 14, wherein aprotector is secured to the speaker frame to protect the speaker unit.16. The speaker device according to claim 14, wherein a metallic plateis disposed on the front surface of the magnetic member to induce amagnetic field to be distributed toward the voice coil.
 17. The speakerdevice according to claim 12, wherein the frame cover has asubstantially flat-plate shape.
 18. The speaker device according toclaim 12, wherein the speaker frame is injection molded and theresonance space has one open side formed by coupling the frame cover tothe rear side of the speaker frame.
 19. The speaker device according toclaim 12, wherein the speaker frame and the frame cover have groovesthat face each other to form the duct hole when the frame cover iscoupled to the speaker frame.
 20. The speaker device according to claim12, wherein the duct hole is formed such that the duct hole opens towardan axis through a center of the speaker device.
 21. A speaker device foruse in a mobile terminal, comprising: a front space; a resonance spaceseparated from the front space; and a speaker unit to emit sound suchthat sound output in a first direction is emitted to the front space,and sound output in a second and substantially opposite direction isemitted through the resonance space.
 22. The speaker device according toclaim 21, wherein the speaker unit is mounted in a speaker frame. 23.The speaker device according to claim 22, wherein the front space isformed in the speaker frame.
 24. The speaker device according to claim23, wherein a frame cover is connected to the speaker frame such thatthe resonance space is formed between the speaker frame and the framecover;
 25. The speaker device according to claim 24, wherein a vent holein the speaker frame connects the front space to the resonance space.26. The speaker device according to claim 25, wherein a duct hole isformed between the resonance space and an outer surface of the speakerdevice
 27. The speaker device according to claim 26, wherein a signalcable extends from the speaker unit and passes through the duct hole.28. The speaker device according to claim 24, wherein the speaker unitincludes a yoke disposed approximately at the center of the speakerframe; a magnetic member attached to the front surface of the yoke anddisposed in the front space of the speaker frame; a voice coil disposedaround the magnetic member; and a vibration plate disposed in the frontspace of the speaker frame such that the vibration plate faces themagnetic member and the voice coil.
 29. The speaker device according toclaim 24, wherein a protector is secured to the speaker frame to protectthe speaker unit.
 30. The speaker device according to claim 28, whereina metallic plate is disposed on the front surface of the magnetic memberto induce a magnetic field to be distributed toward the voice coil. 31.The speaker device according to claim 24, wherein the frame cover has asubstantially flat-plate shape.
 32. The speaker device according toclaim 24, wherein the speaker frame is injection molded and theresonance space has one open side formed by coupling the frame cover tothe rear side of the speaker frame.
 33. The speaker device according toclaim 24, wherein the speaker frame and the frame cover have groovesthat face each other to form a duct hole when the frame cover is coupledto the speaker frame.
 34. The speaker device according to claim 26,wherein the duct hole is formed such that the duct hole opens toward anaxis through a center of the speaker device.